The incidence of cancer increased rapidly in the 20th century and the more developed the country the higher the incidence of cancer. Simple foods are, in fact, surprisingly complex and contain powerful phytochemicals (plant chemicals) that can protect us from many diseases, including cancer.
The good news is that cancer does not manifest overnight. It takes many years to develop and goes through various stages, all of which can be prevented through good nutrition. These stages are initiation, promotion, progression, actual cancer, and spread of cancer known as metastasis. Fortunately, the time between the initiation and cancer stages may take as long as 20 years, allowing plenty of time for protective power of natural whole foods to intervene if good nutrition practice is followed.
The first stage, initiation, occurs when genetic material in the cell (DNA) experiences free radical damage from chemical radiation or even some foods. A free radical is simply a molecule with a single unpaired electron in it’s outer orbit . In order to stabilise itself, a free radical "steals" an electron from another atom. This atom then becomes a free radical, ready to steal an electron from another atom. In this way a chain reaction is set up. Examples of free radical damage can be seen in an apple that goes brown after being cut and exposed to air or oils that turn rancid. Antioxidants come to the rescue by donating the missing electron to an atom, thus preventing free radical damage. For example, if you put a cut apple in a solution of vitamin C (an antioxidant vitamin ), it would stay fresh longer. Antioxidants are abundant in a wide range of foods, particularly fruit and vegetables.
Another major line of cancer defence is via the liver. In order for the liver to do it’s job properly various enzymes are needed and these are produced in the body from nutrients in our food. Certain compounds in food can halt it’s growth even after it has begun to develop. In order for a growth to thrive, a network of blood vessels develop (angiogenesis) so that the cancerous cells can receive nutrients and oxygen. Some substances in food can deter this process. Other compounds can cause cancerous cells to destroy themselves (apoptosis) or induce them to return to normal. The value of nutrition does not end here, however, as even after a tumour has become established in the body, certain food compounds can prevent it from spreading to other sites.
The following is a range of natural foods that have been found to possess anti-cancer compounds:
These all contain important antioxidants known as anthocyanidins, of which there are over 150 in the plant world. The fruits with the highest antioxidant capacity were those with blue, black, and purple pigments, such as blueberries, black grapes, blackberries and prunes. Berries contain a phytochemical, ellegic acid believed to prevent abnormal cellular changes and cherries, perillyl alcohol, a compound related to limonene in citrus fruits, but five times more powerful. This phytochemical can induce apoptosis (cell death) during the promotion and progression stages of cancer and encourage cancer cells to regress. Grapes contain resveratrol, found to inhibit cancer initiation, promotion and progression.
These vegetables are considered to be some of the most powerful cancer protectors and include, cabbage, brussel sprouts, broccoli, kale, cauliflower, collard greens and watercress. Cabbage, broccoli and cauliflower were found to be the most protective because they contain a compound called sulphoraphane, which stimulates the liver’s Phase 2 detoxification process. Cruciferous vegetables hold other secrets, when chewed, a compound indole-3-carbinole (13C) is released, helping to protect the body against the damaging effects of oestrogen , reducing the risk of breast cancer. Eating cabbage can alter oestrogen patterns within just five days.
If you’re a curry fan you’ll be pleased to know curcirm in turmeric has been found to prevent cancer in animals and halt the growth of cancer cells in test tube studies.
Although the issue of soya has become controversial, there is a wealth of knowledge supporting evidence to show that it may play an important role in cancer prevention, particularly of breast and prostate. Genistein and daidzein – 2 phytoestrogens (plant oestrogens) in soya are able to reduce the activity of the body’s own oestrogen by binding to oestrogen receptors on breast cells. Another benefit is that it can help extend the length of the first half of the menstrual cycle, thereby lowering the overall levels of oestrogen throughout life. As well as phytoestrogens, soya contains protease inhibitors which have been shown to block cancer-causing protease enzymes.
People who eat fish regularly are less likely to develop cancers particularly of the breast and colon. One reason for this is that Omega-3 essential fatty acids, which increase the production of anti-inflammatory prostaglandins in the body. Vegetarians or those who do not like fish can obtain Omega-3 fatty acids from flax seeds or flax seed oil (one or two tablespoons a day).
The compounds that lend fruit and vegetables their colours are carotenoids. These are potent antioxidants and promote the body’s detoxification of enzymes. Beta – carotene has been noted to stimulate the release of natural killer cells, which hunt down and destroy cancer cells. The red pigment in tomatoes, lycopene, works by quenching the highly damaging free radical singlet oxygen. Research has concluded that a single serving of tomatoes was enough to reduce levels of oxidative damage to DNA within 24 hours. The prevention of prostate cancer, in particular, has been linked to lycopene. Other carotenoids are found in large quantities of carrots, apricots, sweet potatoes, squash and dark leafy green.
Louis Pasteur was the first to identify the antibacterial properties of onions and garlic. However, of garlic’s many beneficial actions, inhibiting the growth of cancer must be the most remarkable. Studies suggest it has the ability to prevent the development of cancers of the breast, colon, skin, stomach, oesophagus and prostate. According to research Garlic can slow down tumour proliferation and induce apoptosis, it also supresses cancer formation and reduces activation and tumour growth. Onions are protective to the body. The red and yellow varieties are rich in flavenoid, quercetin, which has been called, "the king of the flavenoids".
According to the American National Cancer Institute oranges are "a complete package of every class of natural anti-cancer inhibitor know, including carotenoids, terpenes, flavenoids and vitamin C". The peel of citrus fruits contains the cancer inhibitor, limonene, which works by inhibiting both the initiation and promotion stages of cancer.
Green tea, popular in Asia for over 3,000 years has been referred to as "one of the most practical cancer preventives".
The antioxidants in green tea are 100 times more effective than vitamin C and 25 times more effective then vitamin E. It may also stop cancer spreading once developed. For a tumour to spread to other sites, it has to break through the extra-cellular matrix, which holds cells together. To enable this to happen it uses destructive enzymes called Matrix Metallo-Proteinases (MMP’s). One Japenese study found that green tea could inhibit MMP’s significantly and induce apoptosis in several cancer cell lines including those of the stomach and colon, and leukaemia cells.
As you can see much can be done to prevent the disease from forming, growing and even spreading. The best advice is to eat widely from the vast array of colourful fruit and vegetables that are as protective as they are delicious.
Optimum Nutrition
Journal April 2003
Vol 16 No 1.